"Gianluca Varenni" <varenni@polito.it> wrote in message
news:uv4Cb.195214$hV.7311395@news2.tin.it...
> Hi all.
>
> What's the difference, from the OS point of view, between Monitors and
> Mutexes?
>
> I'm almost sure that the Mutex object is a wrapper to the native win32
mutex
> (if I create a named managed Mutex, I can see it with winobj)
>
> Is there a relationship between the win32 native "CriticalSection" and
> Monitors? How are Monitors internally implemented?
>
> Have a nice day
> GV
>
>

"Sherif ElMetainy" <elmeteny.NOSPAM@wayout.net.NOSPAM> wrote in message
news:OeAdPZGwDHA.2136@TK2MSFTNGP10.phx.gbl...
> Hello
>
> As you said the Mutex object is a wrapper to the native win32 mutex,
> The Monitor is very similar to native win32 CriticalSection but is not a
> wrapper to CriticalSection.
>
> The mutex is a kernel object so creating a mutex take more resources and
CPU
> than creating a monitor, because it requires user mode to kernel mode
> transition. The benefit of a mutex is that you can wait for several events
/
> mutexes using either WaitAny or WaitAll, and you can create a named mutex
> that can be used accross 2 or more processes. This applies to both .NET
> mutex and win32 native mutex.
>
> As for Monitor, it works in user mode, so takes less resources and CPU
than
> a mutex. Every object allocated in the heap in .NET framework, has 8 extra
> bytes (for 32 bit systems) 4 bytes are the virtual method table, and the
> other 4 bytes are the synblockindex, the synblockindex is used by the CLR
> for monitor class, and I think the CLR has some internal structure and/or
> tables for acquired locks, I don't know the details though.
>
> Best regards,
> Sherif

>
> "Gianluca Varenni" <varenni@polito.it> wrote in message
> news:uv4Cb.195214$hV.7311395@news2.tin.it...
> > Hi all.
> >
> > What's the difference, from the OS point of view, between Monitors and
> > Mutexes?
> >
> > I'm almost sure that the Mutex object is a wrapper to the native win32
> mutex
> > (if I create a named managed Mutex, I can see it with winobj)
> >
> > Is there a relationship between the win32 native "CriticalSection" and
> > Monitors? How are Monitors internally implemented?
> >
> > Have a nice day
> > GV
> >
> >
>
>

"Gianluca Varenni" <gianluca.varenni@polito.it> wrote in message
news:edNPlhIwDHA.1600@TK2MSFTNGP10.phx.gbl...
>
> "Sherif ElMetainy" <elmeteny.NOSPAM@wayout.net.NOSPAM> wrote in message
> news:OeAdPZGwDHA.2136@TK2MSFTNGP10.phx.gbl...
> > Hello
> >
> > As you said the Mutex object is a wrapper to the native win32 mutex,
> > The Monitor is very similar to native win32 CriticalSection but is not a
> > wrapper to CriticalSection.
> >
> > The mutex is a kernel object so creating a mutex take more resources and
> CPU
> > than creating a monitor, because it requires user mode to kernel mode
> > transition. The benefit of a mutex is that you can wait for several
events
> /
> > mutexes using either WaitAny or WaitAll, and you can create a named
mutex
> > that can be used accross 2 or more processes. This applies to both .NET
> > mutex and win32 native mutex.
> >
> > As for Monitor, it works in user mode, so takes less resources and CPU
> than
> > a mutex. Every object allocated in the heap in .NET framework, has 8
extra
> > bytes (for 32 bit systems) 4 bytes are the virtual method table, and the
> > other 4 bytes are the synblockindex, the synblockindex is used by the
CLR
> > for monitor class, and I think the CLR has some internal structure
and/or
> > tables for acquired locks, I don't know the details though.
> >
> > Best regards,
> > Sherif
>
>
> Thank you!
> I suspected that the monitor used the syncblockindex (I remember of that
> dword when I had a look at the book on Rotor). I think I should have a
look
> at the rotor source code (the main problem is that is HUGE).
>
> Have a nice day
> GV
>
>
> >
> > "Gianluca Varenni" <varenni@polito.it> wrote in message
> > news:uv4Cb.195214$hV.7311395@news2.tin.it...
> > > Hi all.
> > >
> > > What's the difference, from the OS point of view, between Monitors and
> > > Mutexes?
> > >
> > > I'm almost sure that the Mutex object is a wrapper to the native win32
> > mutex
> > > (if I create a named managed Mutex, I can see it with winobj)
> > >
> > > Is there a relationship between the win32 native "CriticalSection" and
> > > Monitors? How are Monitors internally implemented?
> > >
> > > Have a nice day
> > > GV
> > >
> > >
> >
> >
>
>

> Thank you!
> I suspected that the monitor used the syncblockindex (I remember of
> that dword when I had a look at the book on Rotor). I think I should
> have a look at the rotor source code (the main problem is that is
> HUGE).
>
> Have a nice day
> GV
>